Gas discharge picture display panel

ABSTRACT

A gas discharge display panel for self scan circuits in which supply conductors for the cathode groups are provided in the panel itself and are connected to the cathodes, the cathodes themselves no longer being passed through the wall.

United States Patent De Vries et al.

[451 Feb. 25, 1975 GAS DISCHARGE PICTURE DISPLAY PANEL lnventors: Gerhard Heinrich Friedrich De Vries; Johannes Petrus Hornman; Hendrik Kuster; Johannes Van Esdonk, all of Emmasingel, Eindhoven, Netherlands Assignee: U.S. Philips Corporation, New

York, NY.

Filed: Oct. 29, 1973 Appl. No.: 410,829

Foreign Application Priority Data Nov. 28, 1972 Netherlands 7216085 U.S. Cl. 313/188, 313/220 Int. Cl. H0lj 61/02 Field of Search 313/188, 220, 109.5

\ cnmbww I [56] References Cited UNITED STATES PATENTS 3,711,733 1/1973 Skott 313/220 3,790,849 2/1974 Mayer et al 313/188 3,803,439 4/1974 Sasaki et a1 313/188 Primary ExaminerA1fred L. Brody Assistant ExaminerDarwin R. Hostetter Attorney, Agent, or FirmFrank R. Trifari; Carl P. Steinhauser [57] ABSTRACT A gas discharge display panel for self scan circuits in which supply conductors for the cathode groups are provided in the panel itself and are connected to the cathodes, the cathodes themselves no longer being passed through the wall.

6 Claims, 6 Drawing Figures PATENTEDFEH 25 rszs sum 1 m 2 Fig. 3

GAS DISCHARGE PICTURE DISPLAY PANEL The invention relates to a gas discharge panel for displaying readable characters or pictures and comprising a number of cathodes which are present in a first plane and are connected in groups and which extend perpendicular to a number of anodes present in a second plane and possibly a number of auxiliary anodes present in a third plane.

Such a tube and circuit are known, for example, from Electronics, Mar. 2, 1970, pp. 120-125: Dot matrix display features inherent scanning ability, and from Burroughs Bulletin I161: Self Scan Panel Display.

In addition to the anodes and auxiliary anodes, all the cathodes in the known construction are also passed through the panel wall in a vacuum-tight manner. The connection of the cathodes belonging to the same group is effected on the wiring panel. Hence all the cathodes must be connected to contacts of the wiring panel. Since the number of cathodes increases with the number of characters placed on one line, so with the length of the panel, such a construction becomes more expensive as the length increases.

According to the present invention, the cathodes in an above-mentioned gas discharge panel are divided into groups in which the corresponding cathodes of each group are connected to a common current supply conductor which is provided in the panel and is passed through the panel in a vacuum-tight manner. The large number of cathode lead-throughs is thus replaced by a proportionally small number of leadthroughs of the current supply conductors for the cathode groups and for a cathode operating as an ignition electrode, which number of lead-through conductors is only slightly dependent upon the length of the panel. In the case of a much larger length, however, the number of cathode groups must be chosen to be larger since otherwise the time which is available for deionisation becomes too short as a result of the necessary more rapid scanning.

The connection of the cathodes to the common supply conductors can be carried out by means of cupshaped springs which are placed in apertures of the aperture plate present between the cathodes and the supply conductor. The supply conductors for the cathodes are preferably placed in the plane of and parallel to the anodes, namely above and possibly also below the lines of characters or of the picture. Instead of cup springs, differently shaped connection members may also be used, for example, helical springs or coiled springs, metallisation of the wall of the relevant apertures, and the like.

The invention will be described in greater detail with reference to the accompanying drawing, of which:

FIG. I is a diagrammatic partly perspective crosssectional view of a panel connected according to the known method, and

FIG. 2 is a similar cross-sectional view of a panel according to the invention;

FIG. 3 is a cross-sectional view of a connection of a few cathodes and common supply conductors, while FIG. 4 shows a plate for the manufacture of a cup spring,

FIG. 5 is a plan view and .FIG. 6 a cross-sectional view of a cup spring.

Reference numeral 1 in FIG. 1 denotes a base plate on which in this case 7 auxiliary anodes H (l to 7) are present.

At a small distance from said auxiliary anodes H and perpendicular thereto the cathodes K are present. All

I the cathodes are passed through the wall of the panel in a vacuum-tight manner and are connected together on a wiring panel 6 in three groups K (1, 2, 3). the first cathode K0 is an ignition cathode. The cathodes K are provided, for example, on the rear side of the aperture plate 2 which has a large number of apertures 3. The anodes A are provided on the front of the apertured plate or on the upper plate 4 in such manner that they extend perpendicular to the cathodes K and the holes 3 are just between the crossings of anodes A and cathodes K. All the anodes A, the auxiliary anodes H and all the cathodes K are passed through the wall of the tube in a vacuum-tight manner.

In the embodiment shown in FIG. 2, a number of common current supply conductors KT (1, 2, 3) and a supply conductor KTo are provided which may extend parallel to the anodes A and which may be present above and possibly also below the line of characters to be displayed or a picture plane. The number of supply conductors KT is one more than the number of cathode groups, since one conductor serves for the ignition cathode K0. The cathode supply conductors KT must be connected in the panel to the associated cathodes. This may be carried out by means of a contact member which is placed in certain apertures, namely the apertures which are present at the crossings between the cathodes and cathodesupply conductors to be connected. Such a contact member may consist of a cupshaped spring as is shown in FIGS. 3, 5 and 6. Such a spring may be obtained by cutting a sector from a metal disk as is shown in FIG. 4 and forcing through the remaining part of the disk in a conical manner as is shown in FIGS. 5 and 6 in such manner that the height of the cone is larger than the thickness of the aperture plate 2. Such a resilient member may be placed in the said certain apertures 3 so that said members, after placing the panel plates 2 and 4 one on top of the other, bear against the conductors K and KT and thus produce an electric connection between said conductors.

FIGS. 1 and 2 show panels which are suitable, for example, for characters of 7 dots high and 5 dots wide.

In the panels shown, the cathodes are subdivided into three groups so that, in addition to the leadthroughs of the anodes and the auxiliary anodes H, only the three common cathode supply conductors KT and the supply conductor for the ignition cathode Ko need be passed through in a vacuum-tight manner. In particular for large panels having 16 and more characters, the reduction of the number of leadthrough conductors is considerable. For a panel having 256 cathodes, 256 vacuum-tight cathode lead-throughs are also necessary in the case of FIG. 1; in the case of FIG. 2, in which in this case the cathodes are divided into 7 groups, all the cathode lead-throughs are replaced by only 8 leadthroughs for the cathode supply conductors KT.

Although only one embodiment is shown, the construction of the panels and of the contact members may also be different without departingfrom the scope of this invention. For example, the cathodes may be connected to the base plate and the auxiliary anodes may be secured in grooves in said base plates while the anode may be connected to the upper plate. The auxiliary anodes may also be present, if desired, between the cathodes and the anodes or be omitted entirely. The

cup-shaped springs may also. be replaced by differently shaped springs or by a metallisation of the inner wall of the apertures.

What is claimed is:

l. A gas discharge picture display panel comprising a pair of spaced plates defining a hermetically sealed enclosure therebetween filled with an ionizable gas, a first set of electrodes lying in a first plane within said enclosure and extending in a first direction therein, said first set of electrodes being divided into groups, a second set of electrodes within said enclosure lying in a second plane spaced from said first plane and extending in a direction forming an angle with said first direction, and a common conductor lying in a plane spaced from said first plane connecting the electrodes in each of said groups and extending hermetically through said enclosure to a source of potential.

2. A gas discharge picture display panel as claimed in claim 1 further comprising a plate disposed between said first and second set of electrodes having apertures therein at each of the points of intersection of the electrodes of said first and second sets.

3. A gas discharge picture display panel as claimed in claim 2 further comprising a third set of electrodes in a third plane within said enclosure which constitute auxiliary anodes.

4. A gas discharge panel as claimed in claim 2, wherein the common conductors are parallel to and in the same plane as the second set of electrodes and are electrically conductively connected to the electrodes of the first set by means of connection members which are provided in the apertures of the plate present between the first and second set of electrodes.

5. A gas discharge panel as claimed in claim 4, wherein the connection members are cup-shaped springs.

6. A gas discharge panel as claimed in claim 5, wherein the common conductors are present on a side ofa picture plane determined by the second set of electrodes. 

1. A gas discharge picture diSplay panel comprising a pair of spaced plates defining a hermetically sealed enclosure therebetween filled with an ionizable gas, a first set of electrodes lying in a first plane within said enclosure and extending in a first direction therein, said first set of electrodes being divided into groups, a second set of electrodes within said enclosure lying in a second plane spaced from said first plane and extending in a direction forming an angle with said first direction, and a common conductor lying in a plane spaced from said first plane connecting the electrodes in each of said groups and extending hermetically through said enclosure to a source of potential.
 2. A gas discharge picture display panel as claimed in claim 1 further comprising a plate disposed between said first and second set of electrodes having apertures therein at each of the points of intersection of the electrodes of said first and second sets.
 3. A gas discharge picture display panel as claimed in claim 2 further comprising a third set of electrodes in a third plane within said enclosure which constitute auxiliary anodes.
 4. A gas discharge panel as claimed in claim 2, wherein the common conductors are parallel to and in the same plane as the second set of electrodes and are electrically conductively connected to the electrodes of the first set by means of connection members which are provided in the apertures of the plate present between the first and second set of electrodes.
 5. A gas discharge panel as claimed in claim 4, wherein the connection members are cup-shaped springs.
 6. A gas discharge panel as claimed in claim 5, wherein the common conductors are present on a side of a picture plane determined by the second set of electrodes. 